This disclosure relates generally to heating and cooling systems, and more particularly to a distributor assembly positioned between an expansion valve and a multi-circuit evaporator in a heating or cooling system. In a heat pump and refrigeration cycle, refrigerant alternately absorbs and gives up thermal energy as it circulates through the system and is compressed, condensed, expanded, and evaporated. In particular, a liquid refrigerant flows from a condenser, through an expansion device (e.g., expansion valve) and into an evaporator. As the refrigerant flows through the expansion device and evaporator, the pressure of the refrigerant decreases, the refrigerant phase changes into a gas, and the refrigerant absorbs thermal energy. From the evaporator, the gaseous refrigerant proceeds to a compressor, and then back to the condenser. As the refrigerant flows through the compressor and condenser, the pressure of the refrigerant increases, the refrigerant phase changes back into a liquid, and the refrigerant gives up thermal energy. The process is repeated to emit thermal energy into a space (e.g., heat a house) or remove thermal energy from a space (e.g., air condition a house).
Some conventional evaporators have a plurality of refrigerant flow paths or circuits, each flowing through a different portion of the evaporator. Such evaporators, referred to as multi-circuit evaporators, utilize a distributor device or assembly positioned upstream of the evaporator to divide and direct the flow of refrigerant from the expansion device into the plurality of circuits in the evaporator. The distributor assembly also functions to provide substantially equal distribution of gaseous and liquid refrigerant from the expansion device to each circuit of the evaporator and further to provide substantially even distribution of refrigerant to each of the evaporator circuits. Still further, the distributor assembly is configured to generate a pressure drop in the refrigerant flowing therethrough in route to the evaporator so that the pressure of the refrigerant continues to decrease and the refrigerant absorbs thermal energy, expands, and phase changes into a gas.